View Full Version : Strange problem on AWS

Bob Worsley
7-Mar-2021, 11:29 PM
I'm not sure if anyone can answer this but I'm going to post the question and see if it sounds familiar.

DF 19.1 on AWS, running Postgres & Mertech. I'm not sure if any other parameters I should be mentioning.

We've been setting up and testing an application on AWS for a couple of months and up until a couple of weeks ago all was working as expected. I made a new change to the application that the customer requested and now we have a problem. For many years the application has had all comboforms set to Entry_State = False and this never caused any problems for the users because they've been running on Windows 7 workstations and the appearance of the comboforms was non-shadowed. In other words on a W-7 box the comboform looked like a normal control when entry_state was set to false.

When we went to AWS the comboforms adopted a shadowed appearance because that's apparently what they do when running DF on W-10. Given that I set entry_state = true and attempted to find a solution to keep the users from entering anything in them. Another thread (https://support.dataaccess.com/Forums/showthread.php?60856-Change-comboform-non-entry-color) in the forum addressed this and it does work nicely. But then we noticed two of over 20 reports were causing an error when exiting the application - no errors were seen during usage. And, we are only seeing this on AWS, it doesn't occur on any other server that we've tried.


I've attempted to chase this down which is difficult because at this point I don't have direct access for uploading anything to AWS, I have to work through our systems guy. What I've discovered is that for only 2 reports, the entry_state property setting seems to be causing this. I've removed the custom code I mentioned above and if I set entry_state of all 13 comboforms used in the report to entry_state = true I get the above error. Change them to False and no error.

The next step is to try and narrow this down to a single control if possible but that's going to take a while. In the mean time I thought that I'd tell the story in hopes that maybe someone has seen something like this before. The second question is how to track this down other than trial and error? No Studio on AWS at the moment.

Garret Mott
8-Mar-2021, 06:06 AM
If you can't run through the debugger on the server, aren't you pretty much stuck with showlns or writing to a file/table?

Anyway - you're making Windows stop working, not just DataFlex - you should be proud!

Bob Worsley
8-Mar-2021, 08:34 AM
Yeah, up until now I've been removing and adding code to see what affects it. With this showln's and logging don't really help, we either get the error or not.

Thanks, I could do with a little less proud...

Jim Mulenos
19-Mar-2021, 10:36 AM
Bob, we've been running DF19.1 using the DF ODBC6.3 driver and a MySQL8.x server at AWS very intensely for over a year. Two things: (1) The default client (Control Panel > System) is Windows Server 2016 Datacenter, and (2) I have seen this same [Windows Stopped Working] error dialog on exiting a DF EXE and been unable to trace this as it is not consistent. From (2) I believe the error dialog issue is not your driver or back-end.

Bob Worsley
19-Mar-2021, 11:40 AM
Hi Jim,
Our error is quite consistent and the only reason I haven't gone further with it is that at the moment I don't have access to an AWS test environment. We just went live on AWS this week and so far so good and I'm hoping that shortly I will get that test setup and can continue with chasing it. Interesting that you have seen the error but of course we have no idea if it's the same cause. I'll stay in touch with it.

Bob Worsley
23-Mar-2021, 11:05 AM
We've dug deeper into this problem and now don't think that it has anything to do with entry_state in the comboboxes, that seems to just be the catalyst. Jim Mulenos pointed out that it's intermittent on his system but here we can duplicate it every time.

The problem only happens when running our application on Amazon Workspaces, not on any other platform. The version we're using is version of a Windows VM client created and running on a Windows 16 DataCenter server. It does not occur when running on a Windows 19 Datacenter Remote Desktop Amazon server, Windows 7, Window 8.1 or Windows 2012 R2 Standard Remote Desktop host nor on a stand alone Win-10 PC.

We ran Microsoft's Process Monitor and it seems that the problem occurs in the VDFDAEMON.EXE during exiting. If you look at the attached screen shots you can see the difference - the first is a successful exit, the second with the errors. I Googled "werfault" errors and the explanation says the application could be at fault but we haven't had any luck with what it could be. We can provide the .PML files if that would help.



Bob Worsley
6-Apr-2021, 09:59 AM
Bump... No one has any ideas on this? No one has encountered this other than Jim and I?

14-Apr-2021, 10:48 AM
I have had "Windows stops working" on views where every windows control is disabled. I always make sure there's at least one focusable component on a view.

Bob Worsley
14-Apr-2021, 12:24 PM
Hi Sean,
I know what you mean and may have seen that at some point or another but that's definitely not the case here, all involved are normal data entry views or in this case reports